As described in Ser. No. 511,657, an irrigation system involving gated pipe uses rather large diameter pipe extending across the ends of irrigation channels in a field, and valves are positioned at space points along the pipe to deliver water into the irrigation channels as desired. The valve described in this co-pending application is particularly designed and intended to be suitable for use in this environment, and the application discloses techniques for coupling the valve into a rectangular opening in the side of the gated pipe. A rectangular opening is used to orient the valve relative to the pipe.
It has developed, however, that there are special problems in connection with forming a seal between the conduit leading from the valves into the gated pipe because the gated pipe has rectangular openings and because the pipe is accessible only from one side. While the valve and connection arrangement disclosed was operative, the seal was not completely watertight, allowing leakage which severely diminished the effectiveness and economic satisfactoriness of the valve system.